Digital pulse count correction circuit

ABSTRACT

Method and apparatus for linearizing an electrical signal comprising a series of electrical pulses non-linearly related in number to a sensed condition. The series of electrical pulses are counted in groups and a predetermined number of pulses are generated independently for each group of pulses counted. The method and apparatus has particular utility with a net oil analyzer where the condition is the oil/water ratio and where an initial offset is required at an oil/water ratio of one.

I Umted States Patent 1 [111 3,748,446

Gass et al. July 24, 1973 I54] DIGITAL PULSE COUNT CORRECTION 2,92l,7401/1960 Dobbins ct a]. 235/92 CC CIRCUIT 2,886,243 5 1959 Sprague at al.235/197 3,445,840 5/1969 Carlstead 235/92 PL [75] Inventors: Edward W.Gass; Jack a 3,566,685 3/1971 Zimmerman etal. 235 151.34 x PaulLorenzino, all of Duncan; 2,913,179 11/1959 Gordon 235/l50.3 Joseph E.Thomas, Tulsa, all of Okla. [73] Assignee: Halliburton Company, Duncan,Primary Emmiflerchal'les Atkinson ()k1 Assistant Examiner-Edward J. WiseFiled p 1 1971 Attorney-Burns, Doane, Swecker & Mathis [21] Appl. No.:130,375 ABSTRACT [52] US. Cl t 235/15L35 73/194 235,92 Method andapparatus for linearizing an electrical sig- 2355/1503: nal comprising aseries of electrical pulses non-linearly [51] Cl u u n Go" 1/00 GO 7/38related in number to a sensed condition. The series of 581 Fieldoi's'g'nh.............II.... 235/15135 92 PL elecm'cal Pulses are mutedgmuPs and a predeter- 235/92 CC 92 DE 1503. 73/194 E R 1 mined number ofpulses are generated independently 328/311 1 6 for each group of pulsescounted. The method and apparatus has particular utility with a net oilanalyzer [561 Retereuces Cited where the condition is the oil/waterratio and where an initial offset is required at an oil/water ratio ofone.

23 Claims, 9'Drawing Figures FLUID C(XMT ER LIEARIZATION CIRCUIT COUNTERPmmzumz 3.748.446

SHEET 1 UF 4 IO; M U

NET OIL 22 ANALYZER LINEARIZATION CIRCUIT $28 COUNTER -30 FIGI g SIGNALcouomomue MW 25 25 NET OIL ANALYZER INVENTORS EDWARD W. GASS JACKHAMMOND PAUL LORENZINO,JR. JOSEPH E. THOMAS PAIENIEDJULZMQIS 3 148,446

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SEGMENT SELECTOR SR 1"T I56 I .1. .L .l

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b--|Q-- COUNTER l GRWP PULSE COUNTER DIGITAL PULSE COUNT CORRECTIONCIRCUIT BACKGROUND OF THE INVENTION The present invention relates to amethod and apparatus for linearizing a condition responsive digitalelectrical signal and more particularly to a method and pulse countcorrection circuit for a digital net oil analy- ZBI'.

The linearizing method and apparatus of the present invention hasparticular utility and will hereinafter be disclosed in connection witha net oil analyzer. Net oil analyzers are well known in the art andgenerally utilize a radio frequency oscillator having a capacitanceprobe disposed in the fluid for measuring the constituency thereof,i.e., the net volume of oil and water in the well effluent. A signalfrom the net oil analyzer may be nonlinearly related to the net oil inthe fluid by reason of a non-linearity in the digital output signal fromthe condition responsive transducer or in the digital output signal fromthe flow meter utilized to measure gross fluid flow.

The non-linearity of particular importance in net oil systems is relatedto the character of the well effluent. The well effluent is generallypumped to an oil/water separator or settling tank wherein the effluentquickly stratfies into three layers. The lowermost layer issubstantially pure water and is separated by an emulsion of oil andwater from the uppermost layer which is substantially pure oil.Periodically, the fluid from the oil/- water separator is dumped andpassed through a single fluid pipeline having a capacitance probe and aflow meter disposed therein.

The capacitance probe generally utilized in such system is operativeonly when the fluid is more than 50 percent oil, i.e., the waterdroplets are surrounded by oil. In the event that the oil/water ratio isreversed and the droplets of oil are surrounded by water, the electrodesof the capacitance probe tend to short out and will thus provide anerroneous indication of the amount of oil within the fluid.

Since the percentage of oil and water may vary widely in a givenseparator dump, it is difficult to anticipate the volume of fluid ineach of the three layers sequentially passed through the pipeline. Theoutput signal from the capacitance probe during the passage of thesubstantially pure water must, however, be disregarded in order toprovide an accurate indication of the net oil within the well effluent.

It is accordingly an object of the present invention to provide a novelmethod and apparatus for obviating the deficiencies of the prior art andfor linearizing a condition responsive digital signal.

It is another object of the present invention to provide a novel methodand apparatus for correcting the pulse count output of a net oilanalyzer.

It is yet another object of the present invention to provide a novelmethod and apparatus for modifying the output signal of a net oilanalyzer in accordance with the constituency of the fluid analyzed.

It is yet a further object of the present invention to provide a novelmethod and apparatus for increasing the accuracy of the output signalfrom a net oil analyzer.

It is still yet another object of the present invention to provide anovel method and apparatus for linearizing a digital output signal.

These and other objects and advantages will be apparent to one skilledin the art to which the invention pertains from the claims and from thefollowing detailed description when read in conjunction with theappended drawings.

THE DRAWINGS FIG. 1 is a functional block diagram of the apparatus ofthe present invention;

FIG. 2 is a functional block diagram of the net oil analyzer of FIG. 1;

FIG. 3 is a functional block diagram of the linearzation circuit of FIG.1;

FIG. 4 is a functional block diagram of the subtractor of thelinearization circuit of FIG. 3;

FIG. 5 is a functional block diagram of the group pulse counter circuitof the linearziation circuit of FIG.

FIG. 6 is a functional block diagram of the segment selector shiftregister of the linearization circuit of FIG.

FIG. 7 is a functional block diagram of the gating circuit of thelinearization circuit of FIG. 3;

FIG. 8 is a typical graph of capacitance transducer frequency responseplotted against net oil; and,

FIG. 9 is a graph of the number of pulses applied to the group pulsecounter when plotted against the number of pulses produced by thelinearization circuit.

DETAILED DESCRIPTION The present invention may be more easily understoodby reference to the following detailed description of a net oil analyzerlineariza-tion circuit as set in accordance with the following Table ofContents.

TABLE OF CONTENTS I. System (FIGS. 1-3) A. Circuit Description B.Circuit Operation II. Linearization Circuit (FIGS. 4-9) A. CircuitDescription B. Circuit Operation C. Example III. Advantages and Scope ofInvention I. SYSTEM A. Circuit Description With reference now to FIG. 1,the effluent from a conventional separator or settling tank (not shown)is conveyed by way of a pipeline 10 in which is disposed a capacitanceprobe 12 and a flow meter I4.

The capacitance probe 12 may be of the type claimed and described in U.S. Pat. No. 3,523,245 to R.G. Love et al. entitled Fluid MonitoringCapacitance Probe Having The Electric Circuitry Mounted Within TheProbe" and assigned to the assignee of the present invention. Theflowmeter 14 may be of any suitable type such as the turbine massflowmeter disclosed and claimed in U. S. Pat. No. 3,164,020 to EdwardGroner et al. entitled Flowmeter and assigned to the assignee of thepresent invention. alternatively, a suitable positive displacement metermay be employed.

The output signal from the transducer 12 is a series of electricalpulses having a frequency or pulse repetition rate related to thedielectric constant of the fluid flowing within the pipeline 10. Thisdigital output signal f, is applied by way of an output terminal 16 to anet oil analyzer l8 and a linearization circuit 20. The output signalfrom the flowmeter M is likewise a series of pulses having a frequencyor pulse repitition rate related to the volume of fluid flowing throughthe pipeline It). This output signalf is applied by way of an outputterminal 22 to the net oil analyzer l8 and to a gross fluid counter 24.The counter 24 may be any conventional electrical or electro-mechanicalcounter and may, but need not, provide a visual indication of the numberof pulses counted. A suitable counter, for example, is the I-Ieconserial FR967 counter commercially available from Hengstler Numerics,Inc., of Palisades Park, NJ.

The net oil analyzer 18 is desirably of the type disclosed and claimedin U. S. Application Ser. No. 750,675, filed July 5, 1968, entitledFluid Flow Metering Method and System by Zimmerman et al., and assignedto the assignee of the present invention. The output signals from thenet oil analyzer 18 are applied by way of terminals 25 and 26 to thelinearization circuit 20, and the output signal from the linearizationcircuit 20 is applied by way of a terminal 28 to a conventional counter30 similar both in circuitry and operation to the gross fluid counter 24earlier described.

As illustrated in more detail in FIG. 2, the net oil analyzer 18 of FIG.1 receives the input signal f, from the flowmeter 14 by way of the inputterminal 22. The pulses applied to the input terminal 22 are applied byway of a signal conditioning circuit 32 to the trigger input terminal ofa conventional monostable or oneshot multivibrator 34. The circuitry ofthe signal conditioning circuit 32 may be conventional and is designedto provide a steep wave front triggering pulse suitable for operatingthe multivibrator 34. The false output terminal 25 of the multivibrator34 is connected to a like numbered terminal 25 of the net oil analyzer,and the true output terminal 38 of the multivibrator 34 is connected toan input terminal 40 of a conventional two-input terminal AND gate 42.

The pulses in the output signal f from the transducer 12 of FIG. 1 areapplied by way of the input terminal 16 and a signal conditioningcircuit 44 to the other input terminal 46 of the AND gate 42. The signalconditioning circuit 44 may be similar in all respects to the signalconditioning circuit 32 earlier described. The output terminal 88 of theAND gate 42 is connected to the second output terminal 26 of the net oilanalyzer l8.

With reference now to FIG. .3, the output signal f from the transducer12 of FIG. 1 is also applied by way of the terminal 16 to a frequencydetector 50 of the linearization circuit 20. The output signal from thefrequency detector 50 is applied by way of a terminal 52 to a subtractor54 which also receives the output signals from the terminals 25 and 26of the net oil analyzer 18 of FIG. 2.

The output signal taken from the terminal 25 of the multivibrator 34 ofthe net oil analyzer of FIG. 2 is also way of a terminal 64 to thesegment selector shift register 58 and a second output signal is appliedby way of a terminal 65 to the gating circuit 60 which also receives, byway of a terminal 66, the output signal from the segment selector shiftregister 58. The output signal of the gating circuit 60 is the outputsignal from the linearization circuit and is applied by way of theterminal 28 to the counter 30 of FIG. 1.

B. Circuit Operation The system of the present invention, as heretoforedescribed in connection with FIGS. 1-3, is operative to generate packetsof pulses in which the number of packets is related to the fluid flowand in which the number of pulses in each packet is related to theconstituency of the well effluent. The flow related pulses in the signalf are utilized to trigger the monostable multivibrator 34 for apredetermined period of time during which period the output signal fromthe true" output terminal 38 thereof enables the AND gate 42 to pass thecondition responsive pulses from the transducer 12 through the AND gate42 to the output terminal 26. These net oil related output pulses areapplied to the subtractor circuit 54 of the linearization circuit ofFIG. 3.

However, the condition related pulses f are continuously being appliedto the frequency detector of FIG. 3. The frequency detector 50 isconventional in circuitry and operation and is operative to enable thesubtracotr 54 only when the frequency or pulse repetition rate of thecondition response signals exceeds a predetermined value.

The subtractor 54 is operative to subtract a predetermined number ofpulses from the packet of pulses from the net oil analyzer and tothereafter pass a predetermined number of pulses next occurring in thepacket to the counter 30 of FIG. 1 by way of the terminal 62 and thegating circuit 60.

The subtractor 54 thereafter passes the remaining pulses in the packetfrom the net oil analyzer 18 to the group pulse counter where the pulsesare counted in groups. The segment selector shift register counts thenumber group and provides a signal to the gating circuit indicating thenumber of the group in which the condition-responsive pulses are beingcounted.

The pulses from the group pulse counter 56 are applied to the gatingcircuit 60 and a number thereof, as determined by the number of theparticular group then being counted, are passed through the gatingcircuit 60 to the counter 30 of FIG. 1.

In summary then, no pulses are passed through the subtractor 54 unlessthe frequency detector indicates that the oil/water ratio is greaterthan 1. An initial offset of a predetermined number of pulses is applieddirectly through the gating circuit 60 to the counter 30 and theremaining pulses thereafter occurring in the pulse packet from the netoil analyzer 118 are selectively scaled to correct for anynon-linearity.

II. LINEARIZATION CIRCUIT A. Description The linearization circuit 20 ofFIG. 1 is hereinafter described in more detail in connection with FIGS.4-7. With reference now to FIG. 4, the subtractor 54 of FIG. 3 receivesthe packets of pulses from the net oil analyzer 18 by way of the inputterminal 26. This signal is directly applied to a like numbered terminalof a threeinput terminal AND gate 68 whose output terminal 62 isconnected to the gating circuit 60 of FIG. 7.

The subtractor 54 also receives the false" output signal from terminal25 of the multivibrator 34 of FIG. 2. This signal is applied to thereset input terminal of a counter 72 and to the reset input terminal Rof a bistable multivibrator or flip-flop 73. The packets of pulses fromthe output terminal 26 of the AND gate 42 of FIG. 2 are also applied tothe subtractor 54. These packets of pulses are applied to the counter 72and to one-input terminal of a two-input terminal AND gate 74. Theoutput terminal 70 of the AND gate 74 is connected to the group pulsecounter 56 of FIG. 5.

The counter 72 is conventional both in circuitry and operations and maycomprise a number of serially connected bistable elements. The true andfalse output signals of each of these binary elements are takentherefrom in a manner well known in the art as representative of theirstate of conduction at a particular count. These output signals areavailable, as illustrated, as input signals to two input terminal ANDgates 78 and 80. In the interest of clarity, the connections between theoutput terminals of the counter 72 and the input terminals of the ANDgates 78 and 80 have not been illustrated. The nomenclature adopted forthe various signals is conventional, i.e., the binary numbers 2, 4, 8,16, etc., indicating that a particular flip-flop has a binary logic 1 atthe true output terminal thereof. The presence of a binary 1 outputsignal at the false output terminal is indicated by the binary numberwith a line thereover (1, 2, 4, etc.).

The output signal from the AND gate 78 is applied to the set inputterminal of a bistable multivibrator or flip-flop 82 and the true outputterminal thereof is directly connected to an input terminal 84 of theAND gate 68. The output terminal of the AND gate 80 is directlyconnected to the set input terminal of the flipflop 73 and to the resetinput terminal of the flip-flop 82. The true output terminal of theflip-flop 73 is directly connected to the other input terminal 85 of theAND gate 74.

The output signal from the output terminal 52 of the frequency detector50 of FIG. 3 is applied to a like numbered input terminal of the ANDgate 68.

With reference now to FIG. 5, the pulse group counter 56 of FIG. 3receives the packets of pulses from the subtractor 54 by way of theinput terminal 70. These pulses are applied to a conventional counter 86which may be similar in circuitry and operation to the counter 72earlier described in connection with FIG. 4 and may be internally wiredto reset upon generation of the 16 signal. The counter 86 provides aplurality of binary output signals, each taken from the true or falseoutput terminal of one of the serially connected binary elements withinthe counter 86, and each applied across a capacitor 88 and a resistor 90for shaping purposes. The false 16" or 16 signal is taken from thejunction of the capacitor 88 and the resistor 90 and is directly appliedby way of the termianl 64 to the segment selector shift register 58 ofFIG. 6.

As illustrated in FIG. 5, the binary 1 signal from the counter 86 isdirectly applied to an output terminal 94 and the binary 8 output signalis directly applied to three output terminals 96, 98 and 100. The binary8 output signal is applied together with the binary 16 output signal tothe two input terminals of a OR gate 102 which provides an output signalon the three output terminals 104, 106, and 108. The binary 4 and binary8 signals are applied by way of the two input terminals of an OR gate toan output terminal 112. The binary 4 output signal is also directlyapplied to an output terminal 114. The binary 16 output signal isapplied together with the binary 2 signal to the two input tenninals ofa OR gate 116 and the output signal therefrom is applied to an outputterminal 1 18. The output terminals 96, 98, 104, 106, 108, 114, 112,118, 94 and 100 are connected to the gating circuit 60 of FIG. 7 by wayof the collective terminal 65.

With reference now to FIG. 6, the segment selector shift register 58 ofFIG. 3 receives the 16 signal from the terminal 64 of the counter 86 ofFIG. 5. This 16 signal is applied through a conventional inventer 120 tothe toggle input terminal T of the last one 122 of a series of JKflip-flops -122 serially connected to form a conventional shiftregister. The remaining flip-flops in the series are successivelytoggled by the 16 signal. Two aditional inverters 142 and 144 areinserted between adjacent flip-flops to introduce a short delay and toprevent the toggling of one flip-flop from effecting those subsequentthereto. The first flip-flop 140 in the series is toggled through an ORgate 146.

The segment selector shift register also receives the false outputsignal from the multivibrator 34 of FIG. 2 by way of the terminal 25.This signal is applied to the pre-clear (PC) input terminals of each ofthe flip-flops 140-122, to the set steering input terminal S of thefirst flip-flop 140, and through an inverter 148 to the reset steeringterminal R of the first flip-flop 140 and the other input terminal ofthe OR gate 146.

The false output terminal of each of the flip-flops 140-124 are directlyconnected to the reset steering input terminal of the immediatelyadjacent flip-flop. The true output terminals 150-166 of the flip-flops140-124 are directly connected to the set steering input terminal of theimmediately adjacent flip-flop and also by way of a collective outputterminal 66 to like numbered terminals of the gating circuit 60 of FIG.7.

Referring now to FIG. 7, the input terminals 150-168 are directlyconnected respectively to one input terminal of OR gates -188. The otherinput terminal of the OR gates 170-188 are connected respectively to theoutput terminals 100, 94, 118, 114, 108-104, 98 and 96 of the counter 86of FIG. 5.

The output terminals of the OR 'gates 170-188 are connected through aten input terminal OR gate to the counter 30 of FIG. 1 by way of theterminal 28. Also connected to the output terminal 28 through the ORgate 190 is the output termianl 62 of the AND gate 68 of FIG. 4.

B. Circuit Operation As earlier explained in connection with FIG. 3, afrequency detector 50, e.g., a conventional rate meter, receives thecondition responsive pulses in the output signal f, from the transducer12 FIG. 1 and is operative to provide an enabling signal on the inputterminal 52 of the AND gate 68 of the substractor illustrated in FIG. 4.The AND gate 68 thus receives one of the two necessary enabling signalswhenever the frequency or pulse repetition rate of the output signal f,of the condition responsive transducer is above a predetermined minimum.

The subtractor of FIG. 4 also receives the false" output signal from themultivibrator 34 of the net oil analyzer of FIG. 2. This gating signalis utilized to reset the counter 72 of the subtractor 54 so that thepackets of condition-responsive pulses from the AND gate 42 of the netoil analyzer of FIG. 2 may be counted.

The individual binary elements of the counter 72 are connected to theAND gate 78 in a manner so that the AND gate 78 produces an outputsignal when a predetermined count is attained by the counter 72. Thissignal is used to set the flip-flop 82 thereby providing the secondenabling signal to the AND gate 68 and permitting the passage of thepulses in the packets from the net oil analyzer through the AND gate 68of FIG. 4 and the OR gate 190 of FIG. 7 to the counter 30 of FIG. I.

The counter 72 will continue to count the pulses in the packets ofpulses from the net oil analyzer and will provide, by way of the ANDgate 80, a signal which resets the flip-flop 82 to inhibit the AND gate68 and thereby limit the number of pulses passed through the AND gates68 and 190 to the counter 30.

The AND gate 74 of FIG. 4 is, however, enabled simultaneously with thedisabling of the AND gate 68 and the pulses in the packet of pulses fromthe net oil analyzer are thereafter passed through the enabled AND gate74 to the group pulse counter of FIG. 5. The counter 86 of the grouppulse counter 56 is also reset for the duration of a pulse packet by theoutput signal from the false output terminal 25 of the multivibraotr 34of FIG. 2. The counter 86 accumulates a count of 16 and thereafterinternally resets to begin counting a new group of pulses.

An inhibiting signal is taken from the 16 output terminal 92 of thecounter 86 and is utilized to toggle the selector shift register 58 ofFIG. 6 after each group of 16 pulses has been counted. The various trueoutput terminals of the counter 86 of FIG. are selectively combined inthe OR gates of FIG. 5 and utilized to enable the AND gates of thegating circuit 60 of FIG. 7. Also applied to the AND gates of thecircuit 60 of FIG. 7 are the output signals from the various flip-flopsof the segment selector shift register 58 of FIG. 6. The AND gates ofthe gating circuit of FIG. 7 are thus effective, when enabled by thesegment selector shift register 58 of FIG. 6, to pass the signals takenfrom the counter 86 of FIG. 5 through the OR gate 190 to the counter 30of FIG. 1.

C. Example By way of example, consider the graph of FIG. 8 wherein atypical frequency response curve of a capacitance probe is illustrated.As noted from the graph, the 50 percent net oil point of the curve is ata frequency of 880 kilohertz and the frequency of the transducerthereafter increases to a frequency of 1,026 hilohertz at 100 percentoil. Selecting the gating interval of the net oil analyzer, i.e., theduration of the output pulse from the multivibrator 34 of FIG. 2, to belmillisecond, the number of pulses which can be applied from thetransducer can vary from 880 to 1,026 as the net oil in the welleffluent varies from 50 to 100 percent.

The pulses in a given packet of pulses are applied from the net oilanalyzer of FIG. 2 to the subtractor 54 of FIG. 4 wherein the first 880pulses are utilized to fill the counter 72. The 880 pulses are, ofcourse, required for a 50 percent oil/water ratio. Since it is notdesirable to count the number of pulses in a packet for an oil/waterratio less than 1, the frequency detector 50 generates an enablingsignal only if the transducer 12 senses an oil/water ratio of 1 or more.Thus, the first 830 pulses are not passed through either of the ANDgates 68 or 74 of the subtractor. However, and assuming an enablingsignal from the frequency detector, when the counter 72 reaches a countof 830, an enabling signal is applied, by way of the AND gate 78 andflip-flop 82, to the AND gate 68 and the pulses in the packet from thenet oil analyzer are passed therethrough and through the gating circuit60 to the counter 30. When, however, the counter 72 reaches a count of880, the AND gate resets the flip-flop 82 thereby inhibiting the ANDgate 68 and limiting the number of pulses directly passed to the counter30 to 50 in number. These 50 pulses are introduced into the counter 30in the nature of an offset thereby placing 50 pulses in the counter fora condition of 50 percent oil in lieu of the first 880 pulses of thepulse packet.

The AND gate 80 of the subtractor 54 of FIG. 4 also sets the flip-flop74 thereby enabling the AND gate 74 thereby permitting the passage ofthose pulses in the packet from the net oil analyzer in excess of thenumber 880 through the AND gate 74 to the group pulse counter 56 of FIG.5.

As indicated in the graph of FIG. 9, it is desirable to convert thenumber of pulses in the packet in excess of 880 into a linear curve forapplication to the counter 30. This is accomplished in the illustratedembodiment by dividing the curve into segments of 16 pulses. The logiccircuit of the group pulse counter of FIG. 5, in conjunction with theparticular segment of the curve as indicated by the segment selectorregister 58 of FIG. 6, is operative through the logic circuitry of thegating circuit 60 of FIG. 7 to provide the additional pulses to thecounter.

Reference may be had to the following Table wherein the pulses over 880have a number applied to the group pulse counter of FIG. 5 are tabulatedagainst the number of pulses generated by the gating circuit 60 of FIG.7 for the graph of FIG. 9.

TABLE POINT Pulses Pulses Counted A A 0 50 B 16 S2 2 C 32 54 2 D 48 S7 3E 64 60 3 F 80 63 3 G 96 67 4 H 1 I2 73 6 J 128 82 9 1K 144 98 16 L I46I00 2 Total 50 It may be seen from the above thatthe number of pulsescounted for each of the segments of the curve of FIG. 9 may vary from aminimum of 2 to a maximum of 16 to effect linearization of the curve andthus improve accuracy when the number in the counter 30 is translated bya suitable scaling factor into the desired units of net oil.

ADVANTAGES AND SCOPE OF THE INVENTION From the foregoing detaileddescription to a preferred embodiment, it is apparant that anonlinearity in a digital signal may be corrected by dividing thefrequency response curve into a plurality of segments and utilizinglogic circuitry to provide a specific number of pulses for each of theidentifiable segments. Not only may continually increasing or decreasingnonlinearity be corrected, but a combination of increasing anddecreasing nonlinearities may be accommodated through the logiccircuitry. The size of these segments may be seleted and may be made tovary within the curve as is done, for example, in the illustratedexample wherein 50 pulses are introduced into the counter for the 880pulses in the signal to be linearized.

The linearization circuit heretofore described has particular utilitywhen utilized in combination with a net oil analyzer due to thecharacteristics of the capacitive transducer with respect to the fluidfrom a producing oil well. In such an adaptation, the utility of thetransducer over less than the entire oil/water ratio variation must beconsidered, as must the offset required to place the transducer outputsignal on the desired curve at the time that the accuracy of thetransducer is sufficient for its utilization.

These and other advantages will be apparent to one skilled in the artfrom a perusal of the froegoing as will many modifications within thespirit of the present invention. The present invention is, therefore, tobe limited solely by the language of the appended claims when accordedin full range of equivalents.

What is claimed is:

l. A method of linearizing a digital electrical signal comprising thesteps of:

a. generating a series of electrical pulses non-linearly related innumber to a condition sensed;

b. counting the pulses in said series of electrical pulses in groups,each of the groups including a predetermined number of pulses;

c. generating a predetermined number of electrical pulses for each ofthe groups of pulses counted; and,

d. totaling the number of electrical pulses generated responsively tothe groups of pulses counted to provide a number of electrical pulseslinearly related to the condition sensed.

2. The method of claim 1 including the step of providing an initialoffset by:

counting a first predetermined number of pulses in the series ofelectrical pulses prior to counting the pulses thereof in groups; and,

generating a predetermined number of electrical pulses in response tothe counting of the first predetermined number of pulses in said seriesof electrical pulses.

3. The method of claim 2 wherein the first predetermined number ofelectrical pulses in larger than the predetermined number of electricalpulses counted in groups, and,

a. wherein the predetermined number of pulses in each of the groups isequal to the predetermined number of pulses in each of the other groups.

4. The method of claim 1 wherein the predetermined number of pulses ineach of the groups is equal to the predetermined number in each of theother groups.

5. A method of linearizing a digital signal nonlinearly related to acondition sensed comprising the steps of:

a. generating a first series of pulses non-linearly related in number tothe condition sensed;

b. counting the pulses in the first series of pulses in groups, each ofsaid groups having a predetermined number of pulses; and,

c. generating a second series of pulses related in number to the numberof pulses in said first series of pulses by a factor independentlyrelated to the group in which the pulses in said first series of pulsesare counted.

6. A method of compensating a manifestation of fluid flow for a variablephysical condition of the fluid comprising the steps of:

a. generating a first series of electrical pulses related in number tofluid flow;

b. generating a second series of electrical pulses related in number toa condition of the fluid;

c. generating a third series of electrical pulses responsively to thefirst and the second series of electrical pulses, the number of pulsesin the third series of electrical pulses being non-linearly related innumber either to the volume of fluid flow or to the condition of thefluid;

d. counting the pulses in said third series of electrical pulses ingroups;

e. generating a predetermined number of electrical pulses for each groupof pulses counted; and,

f. manifesting the number of generated group related electrical pulsesto manifest fluid flow compensated for a variable condition of thefluid.

7. The method of claim 6 including the steps of:

a. counting a first predetermined number of pulses in the series ofelectrical pulses prior to counting the pulses thereof in groups; and,

b. generating a predetermined number of electrical pulses in response tothe counting of the first predetermined number of pulses in said seriesof electrical pulses.

8. The method of claim 7 wherein the first predetermined number ofelectrical pulses is larger than the predetermined number of electricalpulses counted in groups, and,

a. wherein the predetermined number of pulses in each of the groups isequal to the predetermined number of pulses in each of the other groups.

9. The method of claim 8 wherein the condition of the fluid is theconstituency thereof.

10. The method of claim 6 wherein the predetermined number of pulses ineach of the groups is equal to the predetermined number in each of theother groups.

11. Apparatus for compensating a manifestation of fluid flow for avariable condition of the fluid compris means for generating a firstseries of electrical pulses related in number to fluid flow;

means for generating a second series of electrical pulses related innumber to a condition of the fluid;

means responsive to said first and second series of electrical pulsesfor generating a third series of electrical pulses non-linearly relatedin number to either fluid flow or to said condition of the fluid;

means for generating a fourth series of electrical pulses related innumber to the number of pulses in said third series of electrical pulsesby a factor related to the number of pulses in said third series ofelectrical pulses; and,

means for counting the pulses in said fourth series of electricalpulses.

12. The apparatus of claim 11 wherein said fourth series of electricalpulses generating means includes means for counting the number of pulsesin said third series of electrical pulses; and,

wherein said factor is the identity of a group of pulses in which thepulse in said third series of electrical pulses is counted.

13. The apparatus of claim l2 wherein said fourth series of electricalpulses generating means further includes means for inhibiting thecounting of pulses in said third series of electrical pulses in groups,said inhibiting means being responsive to the pulse repetition rate ofsaid second series of electrical pulses.

14. The apparatus of claim 13 wherein said fourth series of electricalpulses generating means further includes means for applying apredetermined number of pulses to said counting means responsively tosaid inhibiting means.

15. The apparatus of claim l4 wherein said fourth series of electricalpulses generating means includes:

a frequency detector responsive to said second series of electricalpulses;

a group pulse counter;

a gating circuit;

a subtractor circuit responsive to said frequency detector and saidthird series of electrical pulses for applying a predetermined number ofelectrical pulses to said gating circuit and for applying a number ofpulses to said group pulse counter, said number being less than thenumber of pulses in said third series of electrical pulses but relatedthereto; and,

a segment selector responsive to said group pulse counter for applyingto said gating circuit a signal related to the number of groups counted,

said gating circuit being responsive to said segment selector and tosaid group pulse counter for generating said fourth series of electricalpulses.

16. The apparatus of claim 15 wherein said subtractor includes:

a counter;

first and second bistable elements;

first and second AND gates connected respectively to said first andsecond bistable elements;

a third AND gate responsive to said counter for setting said firstbistable element; and,

a fourth AND gate responsive to said counter for set ting said secondAND gate and for resetting said first AND gate.

17. The apparatus of claim 16 wherein said third series of electricalpulses is applied to said first and second AND gates; and,

wherein said first AND gate is also responsive to said frequencydetector.

18. The apparatus of claim 17 wherein said group pulse includes:

a counter and logic circuit means;

wherein said segment selector includes a shift register; and,

wherein said gating circuit includes a plurality of AND gates and an ORgate.

19. A linearizing circuit for a digitalelectrical signal comprising:

a frequency detector;

a subtractor connected to said frequency detector and adopted to receivesaid digial signal;

a group pulse counter connected to said subtractor;

a segment selector connected to said group pulse counter; and,

a gating circuit connected to said subtractor, to said group pulsecounter, and to said segment selector.

20. The apparatus of claim 19 wherein said subtractor includes:

minal of said first AND gate is connected to said frequency detector.

22. The apparatus of claim 21 including a third bistable element,

said subtractor, said group pulse counter, and said segment selectorbeing enabled by said third bistable element.

23. A method of displaying a pulse count less than the number of pulsesin a series of pulses comprising the steps of:

a. providing a series of pulses;

b. counting a predetermined number of the pulses in the series of pulseswhich occur within a predetermined period of time;

c. counting the pulses in the series of pulses which occur in the sameperiod of time subsequent to the counting of the predetermined number ofpulses; and,

d. displaying a count related to the pulses counted in the same periodof time in excess of the predetermined number of pulses.

1. A method of linearizing a digital electrical signal comprising thesteps of: a. generating a series of electrical pulses non-linearlyrelated in number to a condition sensed; b. counting the pulses in saidseries of electrical pulses in groups, each of the groups including apredetermined number of pulses; c. generating a predetermined number ofelectrical pulses for each of the groups of pulses counted; and, d.totaling the number of electrical pulses generated responsively to thegroups of pulses counted to provide a number of electrical pulseslinearly related to the condition sensed.
 2. The method of claim 1including the step of providing an initial offset by: counting a firstpredetermined number of pulses in the series of electrical pulses priorto counting the pulses thereof in groups; and, generating apredetermined number of electrical pulses in response to the counting ofthe first predetermined number of pulses in said series of electricalpulses.
 3. The method of claim 2 wherein the first predetermined numberof electrical pulses in larger than the predetermined number ofelectrical pulses counted in groups, and, a. wherein the predeterminednumber of pulses in each of the groups is equal to the predeterminednumber of pulses in each of the other groups.
 4. The method of claim 1wherein the predetermined number of pulses in each of the groups isequal to the predetermined number in each of the other groups.
 5. Amethod of linearizing a digital signal non-linearly related to acondition sensed comprising the steps of: a. generating a first seriesof pulses non-linearly related in number to the condition sensed; b.counting the pulses in the first series of pulses in groups, each ofsaid groups having a predetermined number of pulses; and, c. generatinga second series of pulses related in number to the number of pulses insaid first series of pulses by a factor independently related to thegroup in which the pulses in said first series of pulses are counted. 6.A Method of compensating a manifestation of fluid flow for a variablephysical condition of the fluid comprising the steps of: a. generating afirst series of electrical pulses related in number to fluid flow; b.generating a second series of electrical pulses related in number to acondition of the fluid; c. generating a third series of electricalpulses responsively to the first and the second series of electricalpulses, the number of pulses in the third series of electrical pulsesbeing non-linearly related in number either to the volume of fluid flowor to the condition of the fluid; d. counting the pulses in said thirdseries of electrical pulses in groups; e. generating a predeterminednumber of electrical pulses for each group of pulses counted; and, f.manifesting the number of generated group related electrical pulses tomanifest fluid flow compensated for a variable condition of the fluid.7. The method of claim 6 including the steps of: a. counting a firstpredetermined number of pulses in the series of electrical pulses priorto counting the pulses thereof in groups; and, b. generating apredetermined number of electrical pulses in response to the counting ofthe first predetermined number of pulses in said series of electricalpulses.
 8. The method of claim 7 wherein the first predetermined numberof electrical pulses is larger than the predetermined number ofelectrical pulses counted in groups, and, a. wherein the predeterminednumber of pulses in each of the groups is equal to the predeterminednumber of pulses in each of the other groups.
 9. The method of claim 8wherein the condition of the fluid is the constituency thereof.
 10. Themethod of claim 6 wherein the predetermined number of pulses in each ofthe groups is equal to the predetermined number in each of the othergroups.
 11. Apparatus for compensating a manifestation of fluid flow fora variable condition of the fluid comprising: means for generating afirst series of electrical pulses related in number to fluid flow; meansfor generating a second series of electrical pulses related in number toa condition of the fluid; means responsive to said first and secondseries of electrical pulses for generating a third series of electricalpulses non-linearly related in number to either fluid flow or to saidcondition of the fluid; means for generating a fourth series ofelectrical pulses related in number to the number of pulses in saidthird series of electrical pulses by a factor related to the number ofpulses in said third series of electrical pulses; and, means forcounting the pulses in said fourth series of electrical pulses.
 12. Theapparatus of claim 11 wherein said fourth series of electrical pulsesgenerating means includes means for counting the number of pulses insaid third series of electrical pulses; and, wherein said factor is theidentity of a group of pulses in which the pulse in said third series ofelectrical pulses is counted.
 13. The apparatus of claim 12 wherein saidfourth series of electrical pulses generating means further includesmeans for inhibiting the counting of pulses in said third series ofelectrical pulses in groups, said inhibiting means being responsive tothe pulse repetition rate of said second series of electrical pulses.14. The apparatus of claim 13 wherein said fourth series of electricalpulses generating means further includes means for applying apredetermined number of pulses to said counting means responsively tosaid inhibiting means.
 15. The apparatus of claim 14 wherein said fourthseries of electrical pulses generating means includes: a frequencydetector responsive to said second series of electrical pulses; a grouppulse counter; a gating circuit; a subtractor circuit responsive to saidfrequency detector and said third series of electrical pulses forapplying a predetermined number of electrical pulses to said gatingcircuiT and for applying a number of pulses to said group pulse counter,said number being less than the number of pulses in said third series ofelectrical pulses but related thereto; and, a segment selectorresponsive to said group pulse counter for applying to said gatingcircuit a signal related to the number of groups counted, said gatingcircuit being responsive to said segment selector and to said grouppulse counter for generating said fourth series of electrical pulses.16. The apparatus of claim 15 wherein said subtractor includes: acounter; first and second bistable elements; first and second AND gatesconnected respectively to said first and second bistable elements; athird AND gate responsive to said counter for setting said firstbistable element; and, a fourth AND gate responsive to said counter forsetting said second AND gate and for resetting said first AND gate. 17.The apparatus of claim 16 wherein said third series of electrical pulsesis applied to said first and second AND gates; and, wherein said firstAND gate is also responsive to said frequency detector.
 18. Theapparatus of claim 17 wherein said group pulse includes: a counter andlogic circuit means; wherein said segment selector includes a shiftregister; and, wherein said gating circuit includes a plurality of ANDgates and an OR gate.
 19. A linearizing circuit for a digital electricalsignal comprising: a frequency detector; a subtractor connected to saidfrequency detector and adopted to receive said digial signal; a grouppulse counter connected to said subtractor; a segment selector connectedto said group pulse counter; and, a gating circuit connected to saidsubtractor, to said group pulse counter, and to said segment selector.20. The apparatus of claim 19 wherein said subtractor includes: acounter; first and second bistable elements; first and second AND gatesconnected respectively to said first and second bistable elements; athird AND gate responsive to said counter for setting said firstbistable elements; and, a fourth AND gate responsive to said counter forsetting said second AND gate and for resetting said first AND gate. 21.The apparatus of claim 20 wherein one input terminal of said first ANDgate is connected to said frequency detector.
 22. The apparatus of claim21 including a third bistable element, said subtractor, said group pulsecounter, and said segment selector being enabled by said third bistableelement.
 23. A method of displaying a pulse count less than the numberof pulses in a series of pulses comprising the steps of: a. providing aseries of pulses; b. counting a predetermined number of the pulses inthe series of pulses which occur within a predetermined period of time;c. counting the pulses in the series of pulses which occur in the sameperiod of time subsequent to the counting of the predetermined number ofpulses; and, d. displaying a count related to the pulses counted in thesame period of time in excess of the predetermined number of pulses.